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制备了碳纤维增强水泥基复合材料,在SEM扫描电镜下观察了样品的断口形貌。利用NRL测试系统测试了低频段4～8GHz和高频段8～18GHz条件下、碳纤维质量分数分别为0.2%,0.4%,0.6%,0.8%,1.0%时,复合材料对电磁波的反射率,评价了电磁干扰性能。结果表明,低频段时所测得的反射率均小于-10dB,材料对电磁波主要表现出吸收性;高频段且碳纤维质量分数超过0.6%时,反射率大于-10dB,材料对电磁波主要表现出反射性。反射率随着碳纤维质量分数的增加而变化,低频段且碳纤维质量分数为0.6%时,出现最小反射率,其大小为-15.1dB;高频段且碳纤维质量分数为0.4%时,出现最小反射率,其大小为-19.3dB。
The carbon fiber reinforced cement matrix composites were prepared and the fracture morphology of the samples was observed under SEM scanning electron microscope. The NRL test system was used to test the reflectivity of the composites against electromagnetic waves at low frequency band of 4 ~ 8GHz and high frequency band of 8 ~ 18GHz with carbon fiber mass fraction of 0.2%, 0.4%, 0.6%, 0.8% and 1.0% Electromagnetic interference performance. The results show that the reflectivity measured in the low frequency range is less than -10dB, the material mainly shows the absorption of the electromagnetic wave; the reflectivity is higher than -10dB in the high frequency range and the carbon fiber mass fraction exceeds 0.6%, the material mainly reflects the electromagnetic wave Sex. The reflectivity changes with the increase of the mass fraction of carbon fiber. When the mass fraction of carbon fiber is 0.6%, the minimum reflectivity appears and the size is -15.1dB. When the mass fraction of carbon fiber is 0.4%, the minimum reflectivity , Its size is -19.3dB.